It will help if you poly bush the subframe shouldnt get much squeek, its mainly a-arms, control arms and anti roll bars that do, but most companies use graphite in the bush to minimise noise. If you do poly bush you have to do the lot or the oem bushes will not last long. You can fit anything with SFC's. Depends what kind of ride you want but if you want it as good as a corvette you have to spend some serious £££££